Britain would be "extremely concerned" if Spain refuels a Russian carrier battle group heading through the Mediterranean towards Syria, British Defence Secretary Michael Fallon said on Wednesday.

Britain is sending warships to watch a Russian aircraft carrier group and other vessels as they sail through the North Sea and the English Channel. (Source: AP)

Britain would be “extremely concerned” if Spain refuels a Russian carrier battle group heading through the Mediterranean towards Syria, British Defence Secretary Michael Fallon said on Wednesday.

“We’d be extremely concerned that any NATO member should consider assisting a Russian carrier group that might end up bombing Syrian civilians,” Fallon told reporters. “On the contrary, NATO should be standing together.”